Multi-layered waveguide for capturing solar energy

摘要

A waveguide for use in solar power systems to capture sunlight without solar tracking. The waveguide includes a first transparent layer with a first surface receiving sunlight, and the waveguide includes a second surface, opposite the first surface of the first layer, including recessed surfaces (or “microstructures”) each defined by sidewalls extending from the second surface toward the first surface of the first layer. The waveguide includes a second layer of transparent material with a first surface proximate to the second surface of the first layer for receiving a portion of the sunlight transmitted through the first layer. The second layer has a second surface, opposite the first surface, including recessed surfaces of the same or differing shape, size, location, and orientation as those of the first layer. The recessed surfaces of the first and second layers capture sunlight of differing ranges of incidence angles with total internal reflection (TIR).

主权项

1. A waveguide for use in solar power systems to capture sunlight, comprising:
a first layer of substantially transparent material with a first thickness, wherein the first layer has a first surface that is exterior for receiving sunlight and a second surface, opposite the first surface of the first layer, comprising a plurality of recessed surfaces each defined by one or more sidewall extending from the second surface toward the first surface of the first layer; and a second layer of substantially transparent material with a second thickness, wherein the second layer has a first surface proximate to the second surface of the first layer for receiving a portion of the sunlight transmitted through the first layer toward the second layer and wherein the second layer has a second surface, opposite the first surface of the second layer, comprising a plurality of recessed surfaces each defined by one or more sidewall extending from the second surface toward the first surface of the second layer, wherein the recessed surfaces of the first layer are configured to trap at least a portion of the sunlight in the first layer with total internal reflection (TIR), wherein the recessed surfaces of the second layer are configured to trap at least a portion of the sunlight transmitted through the first layer toward the second layer with TIR, wherein the recessed surfaces have sidewalls defining symmetric pyramids, wherein the recessed surfaces of the first layer provide TIR of light striking the first surface of the first layer in a first range of incidence angles, wherein the recessed surfaces of the second layer provide TIR of light striking the first surface of the first layer in a second range of incidence angles differing from the first range of incidence angles, wherein the heights of the recessed surfaces defined by the sidewalls of the recessed surfaces are equal within each of the first and second layers and differ between the first and second layers, and wherein spacing between adjacent ones of the recessed surfaces differs between the first and second layers.